An airbag serves to relieve an impact on an occupant by suitable expansion of an airbag cushion in the event of a vehicle accident so as to reduce or prevent injuries to the occupant. A plurality of airbags may be installed around occupants so as to be expanded and deployed in various forms.
That is, a vehicle may be provided with a basic front airbag which is deployed in front of a driver seat and a passenger seat, a curtain airbag and a side airbag which are deployed at lateral sides of occupants to protect the occupant, a knee airbag for protecting knees of the occupants, and the like.
Expansion behaviors of the airbags are very important to secure safety of the occupants, and thus the occupants are safely protected due to suitable expansion and deployment of the airbags according to collision directions.
A conventional airbag device is designed to deploy an airbag cushion on the basis of a state in which a seat back is fixed at a suitable angle to drive a vehicle. For this reason, it is difficult to safely protect occupants by a deployment manner of the conventional airbag cushion in a state in which the seat back is excessively tilted rearward or a seat is fully moved forward or rearward.
For example, if an autonomous vehicle is commercialized for the future and thus the vehicle automatically travels without a need to directly drive the vehicle by a driver, an inner space of the vehicle is changed from a space for driving to a space for relaxation. For this reason, since the vehicle travels in a state in which the seat back of the driver seat is tilted rearward as shown in FIG. 1, boarding postures of the occupants may be freely changed.
That is, when a collision accident occurs in the state in which the boarding postures of the occupants are freely changed, the occupants may not be safely protected through the existing airbag deployment manner. Therefore, an occupant protection system optimized for the changed boarding postures is required.
The matters described as the related art have been provided only for assisting the understanding for the background of the present invention and should not be considered as corresponding to the related art already known to those skilled in the art.